Overview
Osmundea pinnatifida is a small red seaweed in the family Rhodomelaceae, growing as a tough, cartilaginous, flattened thallus 1–3 inches (2–8 cm) tall attached to rock by a small disc-shaped holdfast. The fronds branch in a regular pinnate pattern, with short opposite side branches giving a feather-like outline, and range in colour from yellow-green and olive in bright sun to dark purplish-brown and red in shade. The texture is firm and slightly fleshy. It grows attached to bedrock and stones on the middle and lower shore, in rock pools and on surfaces wetted by spray, and it withstands repeated exposure to air at low tide. Plants are perennial from the holdfast, with the upright fronds renewing through the year and most growth in spring and summer. The species is gathered as an edible seaweed with a sharp, peppery, garlic-like flavour, eaten fresh or dried as a seasoning. It is sensitive to scouring by sand and to pollution, so it is patchy on disturbed or silted shores.
Native Range
Native to the north-eastern Atlantic, from the British Isles and Scandinavia south to North Africa, and into the Mediterranean. It grows on rocky shores throughout this range.Suggested Uses
Osmundea pinnatifida is gathered as an edible seaweed and used fresh or dried as a peppery seasoning in coastal and foraging cuisine. It also forms part of the grazing food web on rocky shores, where it is eaten by limpets and other invertebrates.How to Identify
Appearance
Size & Dimensions
Height1" - 3"
Bloom Information
As a seaweed, Osmundea pinnatifida does not flower. It reproduces through the red-algal life cycle, alternating between spore-bearing and gamete-bearing stages, with reproductive structures developing on the fronds mainly in spring and summer. New upright fronds also grow back from the persistent holdfast.
Detailed Descriptions
Foliage Description
yellow-green to purple-brownGrowing Conditions
Water & Climate
Water Needs